The German champion, who retired in 2012, is in a medically induced coma after suffering head injuries during a fall in the resort of Meribel last Sunday.

His helmet cracked on impact when he hit a rock while skiing off-piste.

'Respect privacy'

The Sabine Kehm statement read: "Michael's condition remains critical but stable. We would like to clearly stress that any information regarding Michael's health not coming from the doctors treating him or from his management must be treated as invalid and pure speculation."

"The family cares only for Michael's health."

On Friday, some media quoted Schumacher's friend, former F1 driver Philippe Streiff, as saying that he had been told by the Schumacher family doctor, Gerard Saillant, that Michael's life was no longer in danger.

The Kehm statement continued: "Michael's helmet camera was voluntarily given to the investigating authorities by the family. That this should have been done against the wishes of the family is untrue."

Investigators in France are examining the camera.

The authorities are hoping the device may reveal clues about the circumstances of the accident, although it remains unclear whether the camera was switched on at the time.

Police also interviewed Schumacher's teenage son, who witnessed the crash.

The management statement concluded by saying: "In consultation with the doctors treating Michael, it is not expected that there will be any press conference before Monday.

The statement follows quotes attributed to Philippe Streiff

Fans projected the message 'Schumi, stay strong, keep fighting' on to the hospital on Friday

"We ask you to respect the continued privacy of the family."

On Friday, fans held a vigil outside the French hospital treating the former champion to mark his 45th birthday, holding a one-minute silence in the afternoon.

Schumacher has had two operations to remove blood and pressure from his brain.

Doctors have ruled out giving a prognosis for his condition in the coming days and months.

But it is medically possible for someone to spend several weeks in an induced coma and make a full recovery.

Michael Schumacher won seven world championships and secured 91 race victories during his 19-year career.

The driver won two titles with Benetton, in 1994 and 1995, before switching to Ferrari in 1996 and going on to win five straight titles from 2000.